Valine, leucine, and isoleucine, among the nine essential amino acids that cannot be synthesized in the human body, are categorized as branched-chain amino acids because they all have branched-chain structures. Unlike the other amino acids that are metabolized mainly in the liver, BCAA is metabolized in muscles. Further, BCAA is the only essential amino acid serving as a muscle energy source. Therefore, recently, there have been attempts to incorporate BCAA into dietary supplements or beverages.
For example, Patent Literature 1 discloses a food composition containing 30% or more of at least one of valine, leucine and isoleucine; 10% or more of arginine; and 30% or more of protein. Patent Literature 1 alleges that this food composition has an effect of enhancing functions of muscular movements during sports or physical labor.
Further, Patent Literature 2 discloses a supplement drink effective for physical fatigue that contains D-ribose and a magnesium salt and/or a branched-chain amino acid.
Further, Patent Literature 3 discloses that a composition containing pantethine and a branched-chain amino acid significantly decreases the blood lactic acid level after physical exercise. Accordingly, Patent Literature 3 provides a composition for reducing fatigue or malaise.